D-Bus testing: fix race in TestCmdline.testSyncFailure2

We used to kill it when it showed the first sign of life via D-Bus log output
- any output! Depending on timing, it may or may not have been able to send
the "target side ready" INFO message. If it did, our strict output check
failed.

Fix that by waiting for that message, which should be the only INFO message
and thus the only one which will appear in the output text, before killing the
process.

test/test-dbus.py

@@ -7901,7 +7901,7 @@ END:VCARD
         # SYNCEVOLUTION_LOCAL_CHILD_DELAY2 should give us that chance.
         self.killed = False
         def output(path, level, text, procname):
-            if self.running and not self.killed and procname == '@client':
+            if self.running and not self.killed and procname == '@client' and text == 'target side of local sync ready':
                 # kill syncevo-local-sync
                 for pid, (name, cmdline) in self.getChildren().iteritems():
                     if 'syncevo-local-sync' in cmdline:
@@ -7942,7 +7942,8 @@ END:VCARD
         if out.startswith('[ERROR] child process quit because of signal 9'):
             out = out.replace('''[ERROR] sending message to child failed: The connection is closed
 ''', '')
-            self.assertEqualDiff(out, '''[ERROR] child process quit because of signal 9
+            self.assertEqualDiff(out, '''[INFO @client] target side of local sync ready
+[ERROR] child process quit because of signal 9
 [ERROR] local transport failed: child process quit because of signal 9
 [INFO] Transport giving up after x retries and y:zzmin
 [ERROR] transport problem: transport failed, retry period exceeded
@@ -7964,7 +7965,8 @@ First ERROR encountered: child process quit because of signal 9
 
 ''')
         else:
-            self.assertEqualDiff(out, '''[ERROR] sending message to child failed: The connection is closed
+            self.assertEqualDiff(out, '''[INFO @client] target side of local sync ready
+[ERROR] sending message to child failed: The connection is closed
 [INFO] Transport giving up after x retries and y:zzmin
 [ERROR] transport problem: transport failed, retry period exceeded
 [INFO] creating complete data backup after sync (enabled with dumpData and needed for printChanges)